Fig. 4
Representative images and quantitative analysis of early hyphal growth in aplD conditional expression mutants following titration of gene expression. 1 × 104 spores/mL were inoculated in 10 µl volumes onto MM supplemented with various concentrations of Dox. Plates were incubated at 30 °C in the dark for 18 h. Representative images are shown for technically triplicated experiments. Under 0 and 0.2 µg/mL Dox, TC18.1 and TC18.3 strains showed short, hyperbranched hyphae which often were swollen at the tip (a). Under these Dox concentrations, ~ 5–18% of quantified hyphae also demonstrated rupturing at the apex (b, c). Representative growth phenotype of the MA70.15 control under all Dox concentrations is given in d. TC18.1 and TC18.3 hyphal length and branching rate were elevated when expressed using 2 or 20 µg/mL Dox. Box–whisker plots depicting hyphal length (µm, e) and branching rate (hyphal length/no. branches, f) are given. Asterix indicate highly significant differences between MA70.15 control and conditional expression isolate using a Student‘s t test. A minimum of 50 hyphae were analysed per strain/condition. Scale bar depicts 10 µm